In 1997 the Child Development Supplement was added to the Panel Study of Income Dynamics (PSID) with the goal of improving our understanding of socio-demographic, psychological, and economic aspects of childhood from a nationally representative longitudinal perspective. The second wave of data for the Child Development Supplement (PSID-CDS-II), which was funded by NICHD, will be collected. Extensive information will be collected on child development from a subset of the 3,563 children and their parents who participated in PSID-CDS-I in 1997. In this proposal, we request funds to enhance PSID-CDS-II on two important dimensions: (1) to increase the sample of low-income,children to include those originally interviewed in the first wave and (2) to develop a more efficient infrastructure for distribution and use of the data set by a broad array of researchers. Specifically, we propose to: 1.Collect the second wave of data for 730 children from PSID's low-income oversample. 2.Provide detailed coding of middle school/high school course enrollment and performance information, and facilitate links to school characteristics data. 3.Enhance use of the complex CDS and PSID data archive by creating a unified Oracle-based PSID/CDS Data Center and on-line tutorial. 4. Develop a cohesive, interdisciplinary network of researchers to facilitate and promote use of the CDS.